1. Field of the Invention
The present invention relates in general to a liquid delivering apparatus and in particular to such a liquid delivering apparatus including a laminated member in which at least one liquid chamber is formed and which includes an oscillating plate, wherein the liquid in the liquid chamber is given sufficient pressure by at least one piezoelectric element even where the piezoelectric element is driven by a relatively low drive voltage, so that the apparatus is capable of delivering or transporting the liquid from the liquid chamber to an exterior of the apparatus. The present invention also relates to a method of producing the liquid delivering apparatus.
2. Discussion of Related Art
As one example of an apparatus which delivers a liquid by actuation of a piezoelectric element, there are known various ink jet recording heads for use on an ink jet recording apparatus. JP-A-11-254681 discloses one example of such an ink jet recording head and a method of producing the same. The ink jet recording head disclosed in the Publication includes a reservoir in which ink supplied from an exterior is stored, a pressure generating chamber to which the ink is supplied from the reservoir via an ink supply port, a closure member (elastic plate) disposed on one of opposite sides of the pressure generating chamber, and a piezoelectric oscillating element. In the disclosed ink jet recording head, the elastic plate is deformed toward the pressure generating chamber by operation of the piezoelectric oscillating element, thereby pressurizing the ink in the pressure generating chamber, so that the ink flowed into a nozzle opening via a nozzle communication hole formed at one of opposite ends of the pressure generating chamber is ejected from the nozzle opening as a droplet.
The pressure generating chamber is located adjacent to an ink-supply-port forming substrate that is provided by a clad member including a first metal layer, a second metal layer formed of a material which has a resistance to corrosion with respect to an etching agent by which the first metal layer is etched, and a third metal layer which has a resistance to corrosion with respect to the ink, the first through third metal layers being laminated or superposed on each other. At a region of the clad member opposed to the reservoir, there is formed a thin-walled portion that is given by the second and third layers. More specifically described, the first layer corresponding to the region is removed by etching so as to form a recess whose bottom is defined by the thin-walled portion.
When the ink in the pressure generating chamber is pressurized, the ink in the pressure generating chamber flows back into the reservoir. In this case, the pressure of the ink in the reservoir may be increased. In the disclosed ink jet recording head, the above-described thin-walled portion is elastically deformed by the pressure of the ink flowed back into the reservoir, thereby avoiding an increase of the ink pressure in the reservoir. Thus, the variation of the pressure of the ink is prevented from propagating to adjacent pressure generating chambers via the reservoir, thereby avoiding deterioration of ink droplet ejecting characteristics of the head due to the pressure variation.